William r



(No Model.)

W. R. PATTERSON.

INSULATING TELEGRAPH GABLES. No. 369,259. Patented Aug. 30 1887.

N. FUSES. Photo- W wxhin tm D. C

UNITED STATES PATENT OFFICE.

\VILLIAM R. PATTERSON, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE YVESTERNELECTRIC COMPANY, OF SAME PLACE.

INSULATING TELEGRAPH-CABLES.

SPECIFICATION forming part of Letters Patent No. 369,259, dated August30, 1887.

Application filed March 21, 1887.

To all whom it may concern.-

Be it known that I, WILLIAM R. PATTER- soN, a citizen of the UnitedStates, residing at Chicago, in the county of Cook and State ofIllinois, have invented a certain new and useful Improvement inInsulating Telegraph- Cables, of which the following is a full, clear,concise,and exact description, reference being had to the accompanyingdrawings, forming a part of this specification.

My invention relates to insulating electric conductors; and its objectis to obtain any desired degree of uniformly low insulation throughoutthe length of the conductors.

My invention is especially applicable to electric conductors which areseparately insulated by some fibrous material saturated with someinsulating-filling and a core of such conductors waterproofed andprotected by an exterior covering of lead, iron, rubber, or othersuitable material. The specific insulating properties of all thematerials employed to insulate such conductors are very high, and a lowdegree of insulation in such cables is generally an indication of someserious defect in the i'nanufacture. This very high insulation is,however, in long cables used for telephonic work, often the cause ofobjectionable crosstalk, since the currents induced on the wires canescape only at the ends where they are grounded. If the insulation wereof such a low degree that these induced currents could disseminatethemselves through the mass of the core, and so that no static chargecould be held, and at the same time high enough to prevent trouble fromdirect escape of current from one wire to another, the conditions wouldbe most favorable for successful working of the cable-lines. If theinsulation is made low by the presence of moisture which has not beenfully removed from the fibers, the current will establish anelectrolytic action which in time Serial No. 231,642.

(X0 model.)

that the fibers which go to make up any particular part of the coveringwill be in exactly the same condition as those in any other part.

The treatment I give the fiber is preferably L by moistening it with asolution from which the water will be removed by the subsequent process,leaving an inert, harmless, and poorly conducting salt or other compounduniformly distributed throughout the insulating fiber. Common salt inwater is such a solution which I have found to answer the purpose; or afinely-divided solid may be scattercd through and upon the fiber, suchas plumbago.

The necessary precautions are to use such a material that when insolution the solution sulation as a preventive ofinduction, leaving ahighly-insulating medium between the conducting-wire and such exteriorcoating. I, however, distribute the poorly-conducting medium uniformlythrough the body of normally high insulating material as well as uponits surface, so that the insulation of the conductor may be made uniformand as low as shall be desired.

In the accompanying drawings, Figure 1 is a perspective viewillustrative of a singlcconductor, a, clothed with a fibrous material,I), which is evenly permeated with salt. Fig. 2 is a sectional view of alead-pipe-covered cable, 0, having seven conductors, each separatelyclothed, as in Fig. 1, and then saturated with paraffinewax, the spacearound the core being filled with paraffine, d, which may be forced. inin any well-known way.

For the purpose of my invention herein it lead tape, orteven an ironpipe might be used as the equivalent of thelead pipe. Any fibrousmaterial, like cotton, hemp, or jute, may be used as the clothing forthe wires. I prefer paraffine as an insulatingwax, though it is evidentthat resin and shellac, tallow, beeswax and resin, and other compoundsmight be used for saturating the fiber and filling the space in the pipeabout the core.

The essential feature of my invention consists in providing a clothingfor the wires that has been impregnated with salt, carbon, or plumbagoevenly distributed, so as to materially reduce the insulation of thedifferent conductors, so that induced currents may escape, so as toprevent injurious crosstalk in the telephone-cables.

It is evident that almost any metallic salt may be used, as common salt,sulphate ot' coppcr,and sal-ammoniac. Thesolution sprinkled upon orotherwise applied to the fiber should be free from acid, so as not torot the fiber, and should be of such character that the water may bereadily expelled. Plumbagodust I preferably apply dry in the form ofdust. The salts are most easily applied in solution, though it isevident that salt properly dried might under suitable conditions besprinkled or dusted upon the fiber.

Sulphides could not be used in paraflinecables on account of thedecomposition of the melted paraffine by the sulphide.

After the moisture is expelled the salt or its equivalent poorconducting material should be inert, so as not to injuriously affect thefiber, the conductors, or the insulating-filling.

The skeins of yarn, before they are wound on the bobbin, may be dippedin brine composed of, say, ten parts of water to one ofsalt. The amountof salt, however, would vary according to the insulation required. \Vhenplumbago is used, I throw on enough of the dust to darken all the fiber.In either case enough of the poor conductor should be mingled with thefiber so that when charges of electricity are sent into the wire througha telephone at intervals, say, of one second, the wire being open at thedistant end, the clicks heard in the telephone will be of substantiallythe same loudness.

Having thus described my invention, 1 claim as new and desire to secureby Letters Patent- 1. The combination, with the conductors of atelegraph or telephone cable, of a fibrous insulating-covering and saltor its equivalent mingled uniformly with the fiber for reducing theinsulation thereof, substantially as described.

2. The combination, with the insulating fiber, ofa salt or itsequivalent free from acid and inert as to the fiber, the conductor, andinsulating paraffiue or wax, said salt being commingled uniformly withthe fiber throughout the length of the cable to lower the insulation ofthe separate conductors, as described.

3. The combination, with the conductors of a telephone-cable, of afibrous insulating ma terial wound upon the separate conductors, afilling of insulating material for protecting the conductors within theoutside pipe or covering, and a poor insulating substance mixed with thefiber uniformly to reduce the insulation and prevent the retention ofthe static charge.

In witness whereof Ihereuuto subscribe my name this 16th day ofFebruary, A. D. 1887.

'WILLIA. LPAJTTERSON.

\Vit ness es:

WM. M. GrLLnR, Gnonen P. BARTON.

